if it was so expensive like you say people wouldnt be paying, but they do..

i have all that and ive never spent any money on zen..

you do not have to pay for anything if you dont want to, this is why i like this game.
all it takes is time and patience.

Yep!

Also, Fleets can look at their contribution leaderboards and REWARD FLEET MEMBERS ACCORDINGLY. In another game, when we needed group resources, I put a bounty up: 1x gave 1y reward up to z. Hey, it can work nicely!